To calculate the pH of a solution of HBr, which is a strong acid that ionizes completely in solution, you can use the formula:
\[ \text{pH} = -\log[\text{H}^+] \]
In this case, since the concentration of HBr is \(1.0 \times 10^{-1}\) M, the concentration of hydrogen ions \([\text{H}^+]\) will also be \(1.0 \times 10^{-1}\) M.
Now, we can calculate the pH:
\[ \text{pH} = -\log(1.0 \times 10^{-1}) \]
Calculating the logarithm:
\[ \log(1.0 \times 10^{-1}) = -1 \]
So,
\[ \text{pH} = -(-1) = 1.0 \]
Thus, the pH of the \(1.0 \times 10^{-1}\) M solution of HBr is:
\[ \text{pH} = 1.0 \]
Since the original concentration was given to two significant figures, we can express the pH with the same significant figures:
\[ \text{pH} = 1.0 \]
So, the answer is 1.0.